Apparatus and process for low-temperature injection of a liquid crop preservative formulation

ABSTRACT

An apparatus and method for treating a substrate with a volatile liquid, crop-preservative formulation, wherein said substrate is in proximity to a crop to be treated by the vapor from said formulation, is disclosed. The substrate is most conveniently a portion of a container in which said crop is stored or shipped. The apparatus and method are adapted to place predetermined quantities of said formulation upon a desired substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is related to U.S. patent application Ser. No.13/743,236, filed Jan. 16, 2013, on even date herewith (Attorney DocketNo. 1957-8885US) entitled: “INJECTABLE LOW-TEMPERATURE LIQUID CROPPRESERVATIVE FORMULATION,” which is incorporated herein in its entiretyby this reference.

FIELD OF THE INVENTION

This invention generally relates to a process and apparatus forindirectly treating crops with vapors from a volatile liquid croppreservative. Particular embodiments also relate to apparatus andmethods for treating potatoes after storage to prevent sprouting duringshipment to warehouses, grocery stores, and the like, especially insmall containers such as cardboard boxes, bags, and the like.

BACKGROUND OF THE INVENTION

Tubers, especially potatoes, are treated with sprout inhibitors duringstorage (see, U.S. Pat. No. 6,010,728). These techniques involve placingupon the potato a residue of a sprout inhibitor, especially CIPC.Currently, potatoes removed from storage are treated directly with asprout inhibitor, such as a water-based formulation of CIPC(chloroisopropyl carbamate). Alternatively, aerosol containers filledwith DMN (dimethyl naphthalene) are placed in trucks to provide anenveloping vapor of DMN during shipment to a store or other destination.

These techniques have shortcomings. Many consumers do not want warepotatoes (potatoes to be consumed as such) to contain CIPC, a syntheticchemical that has EPA restrictions relating to residues on potatoes. TheDMN vapor technique from aerosol containers is effective, but some truckoperators forget to install them in the enclosed truck box. Often, thesepotatoes are placed in cardboard boxes, which are packed tightly in thetruck, minimizing circulation of DMN vapor from an aerosol container.Patents relating to release of DMN vapors include U.S. Pat. Nos.6,541,054, 5,918,537, 6,338,296, and 6,403,536.

BRIEF SUMMARY OF THE INVENTION

The instant invention relates to apparatus and methods for treatingsmall containers, such as cardboard boxes, paper bags, and the like,with a predetermined quantity of a volatile crop preservative chemical.Use of a volatile chemical such as DMN, especially 1,4 DMN, results inits subsequent volatilization to provide a contained-vapor of DMN, forexample, within the cardboard box or other suitable container.

The apparatus and methods are structured to apply a small predeterminedquantity of volatile liquid chemical (e.g., DMN) onto an interiorsurface of a box or any other suitable container. The techniquegenerally involves injecting a predetermined quantity of volatilecrop-preservative chemical onto the interior surface of a cardboard box,paper bag, or similar small container just prior to that box or othercontainer being filled with clean crops (e.g., ware potatoes or othercrops such as berries, onions and the like) prior to shipment to market.

Generally, it is desired that any surface containing a deposit of liquidvolatile chemical be positioned so that it doesn't contact the surfaceof a crop (e.g., potato) to prevent surface damage to such a crop. Onlythe vapors from a deposited predetermined quantity of liquid volatilechemical (e.g., DMN) are intended to reach the potatoes. This vaporgeneration is generated when the liquid volatile chemical is applieddirectly to an interior of a box or other container.

In a particular embodiment, the instant apparatus and process can beintegrated with the continuous or semi-continuous system for fillingcontainers with potatoes. A filling station may place various quantitiesof potatoes in a container; for example, the potato-dispensing machinemay dispense 5 lbs., 20 lbs. or 25 lbs. of potatoes at various periodsof time. A feedback loop from the potato-dispensing machine to thechemical injection apparatus then controls the appropriate quantity,especially the proper amount of active ingredient to be applied to a boxor carton for a particular weight of potatoes.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a block diagram illustrating one embodiment of the invention.

FIG. 2 is a block diagram illustrating the use of a metering pumpaccording to another embodiment of the invention.

FIG. 3 is a block diagram illustrating the use of a metering pumpincluding a feedback loop 22 and a filling station controller accordingto an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

A particular embodiment of the disclosure is made with reference to FIG.1, which illustrates an apparatus and method for applying apredetermined quantity of liquid DMN to the interior surface of a box.The crop to be treated, in one example, is potatoes, in order topreclude or minimize sprouting, dehydration, and/or loss of turgidityduring shipment to market.

Potatoes for shipment to stores (ware potatoes) are generally placed inboxes at a filling station as the boxes are conveyed along a conveyor ina substantially continuous manner. In FIG. 1, such an empty box 17 isshown at a first position. A sensor or trigger 16 senses the position ofan empty box and sends a signal to controller 15, which sends anactuator signal to a solenoid valve 13. Valve 13 can be a metering valveand can be opened for a controlled period of time to cause an injectionof a predetermined, small quantity of DMN or other volatile sproutinhibitor to be injected into box 17 from an injection nozzle 14.Injection nozzle 14 may be structured to squirt a tight stream or afan-like spray of liquid chemical, depending upon the particular depositof chemical desired on the box surface. If the box surface is absorbent,a tight stream of liquid may be applied to penetrate into the absorbentsurface to provide for a time-release effect of the vapor. If the boxsurface is more dense (i.e., less absorbent) a larger imprint ofchemical onto the surface may be applied.

The liquid chemical can be stored in a container 10 to flow by gravitythrough line 12 to pump 11, which provides a pressurized stream ofliquid chemical to solenoid valve 13. A constant pressure of chemicalliquid may be used so that a predetermined amount of liquid chemicalwill be injected through solenoid valve 13 when it is opened for apredetermined period of time. Controller 15 may be pre-set to controlthe amount of time solenoid valve 13 is open, thereby controlling thequantity of liquid chemical, which is ejected from nozzle 14. Aneedle-type valve may be used to control the quantity of liquid ejected.

Pump 11 could be omitted if tank 10 were to be placed at a very elevatedposition above solenoid valve 13, so that gravity (pressure head ofliquid) would provide a sufficient constant pressure of liquid chemicalto solenoid valve 13. In order to have a predetermined quantity ofliquid chemical ejected from nozzle 14, a constant liquid pressure maybe effected on solenoid valve 13.

The quantity of liquid chemical to be injected into the box 17 dependsupon the type of chemical, its efficacy as a crop preservative, theconcentration of active ingredient in the liquid chemical, the quantityand type of crops to be placed in the box, the condition of the crop,and estimated transit time of the box to the ultimate destination of thecrop (e.g., a grocery store).

The filling process may include empty boxes being transported on aconveyor in a continuous manner or, alternatively, in intermittentmovement. In the embodiment of FIG. 1, box 17 is shown in a firstposition where a predetermined quantity of liquid chemical is injectedinto the box. The box is then conveyed to a filling station where apredetermined quantity (weight) of potatoes is dropped into the box. Thepotatoes may be loose or bagged, in plastic or paper bags, which cancontain ventilation pores therein so the potatoes may respire and thechemical vapors can intrude into the bag interior, surround thepotatoes, and then be absorbed thereon. The boxes then proceed toanother station where the boxes are sealed.

The liquid chemical utilized may be a DMN, such as 1,4 DMN, or aformulation that contains a diluent, a solvent, surfactant or otheradditive to achieve a particular purpose. 1,4 DMN is marketed as1,4SIGHT® and may be obtained from 1,4 Group, Meridian, Id. Otheradditions may include aroma enhancers, deodorizers, essential oils,higher alcohols of C₆-C₁₂ carbon length, and the like.

DMN was shown to be effective on sprouting root and tuber cropsincluding, but not limited to, beet, carrot, cassava, dasheen (taro),ginger, ginseng, horseradish, parsnip, potato, sweet potato, turnip, andyam. DMN was also shown to be effective on sprouting bulb cropsincluding, but not limited to, garlic, leek, onion, and shallot. DMN wasalso shown to be effective on sprouting ornamentals, such as floweringbulbs.

A diluent or solvent may be included in the liquid chemical for avariety of purposes. Some active ingredients, such as DMN, are expensiveand a precise quantity is desired to be applied to the interior surfaceof the box. That quantity, for small boxes, may be so small that thesolenoid valve may be open for such a fraction of a second that precisecontrol of liquid ejected is difficult. Thus, a diluted activeingredient in a liquid composition provides for a greater liquidquantity to be ejected and, thereby, enabling a more precise control ofthe quantity of active ingredient (a.i.) to be applied.

Also, a chemical composition containing a diluent may be used toeffectuate a large spray pattern onto the box surface so that theevaporation rate of the active ingredient may be enhanced, if sodesired. Also, other volatile active ingredients may be included in theliquid chemical composition, such as bactericides, fungicides, etc. Theinclusion of surfactants to reduce surface tension and/or viscosity ofthe injectable liquid may be also desirably included in an injectablechemical composition.

Other volatile active ingredients, such as peppermint oil, clove oil,and other known volatile sprout inhibitors, may be included. Theseessential aromatic oils are, generally, sufficiently volatile to beuseful. Other suitable volatile chemicals include aliphatic alcohols,especially those of a molecular size C₆-C₁₂ carbon atom. Aliphaticaldehydes and ketones may also be used, including those disclosed inKnowles, U.S. Pat. No. 6,855,669. Useful essential oils are alsodescribed in U.S. Patents to Vaughn (U.S. Pat. Nos. 5,139,562 and5,129,951), as well as U.S. Pat. No. 5,580,596 to Winkelman, and U.S.Pat. No. 6,313,073 to Farooqi. Also, U.S. Pat. No. 5,334,619 to Vaughndiscloses 2-nonanone as a useful fungicide for treatment of berries.

These chemicals typically have a volatility in about the same range as1,4 DMN and may be utilized in conjunction with 1,4 DMN, either as acompatible mixture or in sequence with 1,4 DMN. The above-identifiedchemicals may also be used separately from 1,4 DMN, either as separateactive ingredients or in admixtures of such chemicals. There arevolatile aromatic chemicals such as pyrazines, which have beenidentified as emanating from baked potatoes, which may impart afavorable baked potato aroma. A minor amount of these compounds could beincluded for favorable aroma purposes, without any adverse effect uponthe sprout inhibiting effect of DMN. Formulations disclosed in copendingU.S. patent application Ser. No. 13/743,236 (Attorney Docket No.1957-8885US), entitled “INJECTABLE LOW-TEMPERATURE LIQUID CROPPRESERVATIVE FORMULATION,” filed contemporaneously herewith by commoninventors and commonly assigned, are especially useful in the instantinvention.

U.S. Pat. No. 6,403,526 disclosed certain deodorant chemicals forinclusion with DMN to mask any residual DMN odor. These chemicals may beincluded in the applied liquid chemical formulation utilized in theinstant disclosure. The contents of that patent are incorporated hereinby reference.

The quantity of active ingredient applied to a box or other smallcontainer will be dependent upon the quantity (weight) of potatoes to beplaced in the box. Typical concentrations of DMN, e.g., range from about0.5 mg per kilogram of potatoes to about 20 mg/kg. Thus, for a boxholding 25 lbs. (approximately 12 kg), about 6.0 to about 250 mg of DMNwould preferably be applied to such a container.

In FIG. 1, the quantity of liquid chemical injected into a box isdetermined by the orifice opening in the valve, the liquid pressure, andtime period for which the valve is open upon receiving an electricalsignal (power input) of the desired duration. These factors can becalculated and modified to give a certain predetermined quantity ofliquid formulation per unit of time that the solenoid valve is open.

Another embodiment of the invention is illustrated in FIG. 2, wherein amicro metering pump 18, e.g., a very small positive displacement(piston) pump, is utilized. Such a pump will displace the contents ofits cylinder on a volume per stroke of its piston. Given the minutequantities of chemical liquid to be injected, the cylinder volume ofsuch a pump can be adjusted to be small (e.g., 0.05 ml). Multiplestrokes of the piston can be used to provide for increased volumes ofliquid chemical to be ejected into a box. Again, use of a diluent toreduce the concentration of active ingredients may permit use ofmicropumps with larger displacement.

A controller 15 controls, by the duration of an electrical signal sentto the pump that indicates the number of times the piston reciprocates,the volume of liquid chemical introduced via injection nozzle 14 into abox, bag or other container with a receptive surface.

The system of FIG. 2 is similar to that of FIG. 1, except that thecontrol liquid ejected is via a metering pump 18. A feedback loop 22from the filling station controller 21 is shown in FIG. 3. A controlfunction associated with the dispensing unit 20, which dispenses acontrolled quantity of potatoes to be discharged from a bin into anawaiting pre-treated box 17, may send a signal via the feedback loop 22to the liquid chemical controller to control the quantity of chemicalinjected into an awaiting empty box 17 sitting upon a continuous orsemi-continuous conveyor 19.

Alternatively, a feedback loop may be associated with a weighingmechanism to send a signal to a liquid chemical control to account for aquantity (weight) of potatoes being placed in the box so that the properquantity of chemical can be injected into a box. Further, the quantityof potatoes discharged into a box and the quantity of chemical ejectedmay be controlled manually to apply the proper quantities.

Many volatile liquid sprout inhibiting chemicals useful in the instantinvention are solvents. For example, a mixture of different DMN isomers,which has been sold by Koch Chemical as a solvent, may be useful.Generally, pure 1,4 DMN, which is available from the 1,4 Group,Meridian, Id., has been the preferred DMN sprout inhibitor/dormancyenhancer used in the potato industry. It has been approved by the EPA.

Given that 1,4 DMN has solvent characteristics, a very minor quantity ofa lubricant in any liquid chemical composition may be included,especially if a metering pump is used for injecting controlledquantities of DMN into a container. Suitable lubricants may includevegetable oils, mineral oils and similar food-grade lubricants,including essential aromatic oils.

Alcohols of various types, e.g., methanol, ethanol, isopropanol, arealso solvents that have been used with respect to potato treatmentchemical compositions. Thus, the use of these alcohols as solvents ordiluents may be included alone or with a small quantity of a lubricant.

Although, “tags” may be treated with an appropriate amount of a liquidchemical composition sprout inhibitor or dormancy enhancer, as indicatedin certain patents referenced above, it is very advantageous to treatthe potato container since such container is large and is less likely toaccidentally become part of a food made from potatoes or otherwiseaccidentally ingested. Also, the instant disclosure forms part of thecontinuous process of filling boxes with potatoes or other crops orproduce to be shipped to market.

An especially desirable feature of 1,4 DMN as an injectable chemical forthe purposes of this disclosure is that it diminishes sprouting ofpotatoes during shipment by dormancy enhancement. This type of action,in contrast to the anti-sprouting effect of CIPC, helps to preservemoisture content in the potatoes, thus providing a firm, turgidhealthy-looking potato to ultimate consumers. Further, it isadvantageous that 1,4 DMN is present in freshly harvested potatoes andis, thus, a naturally occurring ingredient.

The speed at which boxes are moved along a conveyor to a filling stationis quite rapid. The liquid chemical injection systems described andclaimed herein are suitable for rapid operation. The ability of asolenoid valve to eject a predetermined amount of liquid chemical canoccur in fractions of a second. This is also true for a micro-meteringpump. Thus, a liquid chemical ejection system of the present system canbe implemented in a continuously conveyed, container-type filling systemfor potatoes.

The invention may be adjusted on-site via the controller to regulate thequantity of chemical injected into a container in a continuous orsemi-continuous conveyor system. Also, the controller can control theperiod (time lapse) between injections. Thus, the system can beintegrated with the filling system for filling boxes with potatoes, suchas ware potatoes.

The system and method of the instant invention has been described asbeing useful in treating containers to be filled with ware potatoes.Other crops, such as fruits (e.g., pears, peaches, cherries,blueberries, raspberries, blackberries, and strawberries), may beshipped in containers similarly treated by the method and systemdisclosed herein. Berries, such as strawberries, are often contaminatedwith a mold or fungus, which tends to diminish the useful life of such acrop when it reaches an ultimate consumer. Raspberries are particularlyvulnerable to mold formation within about 24 hours of being harvested,if allowed to be at room temperature.

Additional or concurrent treatment of containers for berries with ananti-mold, bactericide or fungicide of a volatile nature may increasethe useful life of such berries in the hands of an ultimate consumer.The use of 1,4 DMN for crops may achieve such purposes as well asmaintain hydration, which is very important for presentation of plump,healthy-appearing berries on a grocer's shelf.

A “volatile” liquid chemical for the purposes of this invention includesone that has a significant vapor pressure at temperatures as low as 40°F. with a significant increase in vapor pressure with increase intemperature. Liquid chemicals having a volatility similar to that ofDMN, especially 1,4 dimethyl naphthalene, are considered to be volatilechemicals for the purposes of this invention.

Given that the purpose of treating a shipping container is to provide anatmosphere of an effective chemical for a particular crop duringshipment, an herbicidal, fungicidal, bactericidal chemical thatsubstantially evaporates during shipment (e.g., over a period of severaldays to a couple of weeks) is sufficiently volatile for the purposes foruse in the disclosed methods and systems.

The apparatus and processes described and claimed herein may be used totreat a wide variety of produce during the filling of boxes, cartons,etc., in preparation for shipment to grocers.

The embodiments described herein are not meant to limit the scope of thepresent invention. In each of the various embodiments, the methods, kitsand system described herein disclose a way for collecting a sample andtransporting the sample to another location for chemical residueanalysis. However, the present invention may be carried out usingembodiments different from those specifically described herein.Therefore, the scope of the present invention is not limited by theexemplary embodiments, but is defined by the appended claims.

1. Apparatus for injecting a predetermined, controlled quantity of a volatile liquid crop-preservative formulation containing a crop-preservative active ingredient onto a substrate comprising: a reservoir for containing a volatile liquid crop-preservative formulation; transport means to transport said volatile liquid formulation from said reservoir to an injection device; an injection device adapted and structured to eject a predetermined quantity of said volatile liquid formulation onto a substrate in a predetermined time period; and control means to control said injection device to eject a predetermined quantity of said volatile liquid formulation.
 2. The apparatus of claim 1, wherein said injection device comprises a miniature positive displacement pump in communication with an ejector nozzle or orifice.
 3. The apparatus of claim 2, wherein said pump has adjustment means to adjust the quantity of ejectable volatile liquid per unit of time.
 4. The apparatus of claim 3, wherein said adjustment means is a mechanical device.
 5. The apparatus of claim 3, wherein said adjustment means is an electrical device.
 6. The apparatus of claim 1, wherein said injection device is a control (metering) valve to control intermittent volume control of liquid to an injection nozzle.
 7. A method for applying an effective amount of a crop-preservative, volatile liquid to a container comprising: calculating a predetermined quantity of a crop to be placed in the container; transporting a pre-determined quantity of said volatile liquid to an application site; and applying said pre-determined quantity of volatile liquid to a container to be filled with said predetermined quantity of crop.
 8. The method of claim 7, wherein the predetermined quantity of said volatile liquid is determined by the quantity of crop to be affected and the concentration of crop-preservative active ingredient in said volatile liquid.
 9. An indirect method of treating a crop with the vapor of a volatile liquid crop-preservative chemical composition comprising: treating a container interior with a predetermined quantity of said volatile liquid crop-preservative chemical composition, wherein the volatile liquid crop-preservative chemical composition substantially vaporizes at the ambient temperatures to which the container is subjected and the pre-determined quantity is determined by the quantity of crop to be placed in said container.
 10. The method of claim 9, wherein said volatile liquid crop-preservative chemical composition comprises dimethyl naphthalene (DMN).
 11. The method of claim 10, wherein the volatile liquid crop-preservative chemical composition comprises 1,4 DMN.
 12. The method of claim 9, wherein said predetermined quantity of volatile liquid crop-preservative chemical composition is placed upon an interior surface in said container.
 13. The method of claim 9, wherein said volatile liquid crop-preservative chemical composition contains an active ingredient that is a sprout-inhibiting chemical effective to reduce sprouting of harvested potatoes.
 14. An apparatus for injecting a predetermined, controlled quantity of a volatile liquid crop-preservative formulation into a container adapted to contain a predetermined quantity of a crop, comprising: a reservoir for containing said volatile liquid crop-preservative formulation; transport means to transport said volatile liquid crop-preservative formulation to an injection device; hydrostatic pressure-inducing means to pressurize said volatile liquid crop-preservative formulation prior to said formulation reaching said injection device; an injection device comprised of a control (metering) valve having an injection nozzle; valve control means to control the opening and closing of said control valve to regulate the frequency and injection of a predetermined quantity of said formulation onto an interior surface of said container.
 15. In a continuous conveyer system for transporting and filling containers with a crop, the improvement comprising: reservoir means for holding a quantity of a liquid chemical crop preservative; conveying means to convey said liquid chemical crop-preservative to an injection means; and injection means having control means to inject a predetermined quantity of the liquid chemical crop preservative into each container of a substantially continuously moving flow of containers.
 16. The system of claim 15, wherein said injection means is a control valve structured and adapted to eject a predetermined quantity of a pressurized liquid chemical with each actuation of said valve by said control means.
 17. The system of claim 15, wherein said control means further controls the periodicity of liquid chemical injections. 